A 75-meter-wide asteroid will pass the Earth of Friday, the third of three 'potentially hazardous' rocks flying past out planet this week. Asteroids 2012 DK31, 2006 BE55, and 2021 QW are all being tracked by NASA as they pass 'close' to Earth.
The first one started moving past us on Monday. It measured about 137 metres in diameter, and is thought to be as wide as the height of a 40-floor skyscraper. The second one started coming close to Earth last night, and is the closest of the three.
That one flies by every four or five years.
The third asteroid will come near Earth on Friday. It will be about 75 meters in diameter, flying about 3.3million miles from the planet, the Daily Star reports.
All three have been labelled Potentially Hazardous Asteroids, which means that they could cause some damage to our planet should the trajectory change in some way - although that's incredibly unlikely.
Richard Moissl, the European Space Agency's head of planetary defence said: “Asteroids the size of the Chelyabinsk meteor strike Earth roughly every 50 to 100 years. Injuries caused by airbursts or similar events could be prevented if people are informed of an oncoming impact and its predicted effects.
“With advance warning, local authorities would be able to advise the public to keep well away from windows and glass.
“New telescopic surveys are braving the sun's glare and searching for asteroids toward the sun during twilight.
“These surveys have found many previously undiscovered asteroids interior to Earth.”
